introduction to windows programming - electrical...

C# Programming: From Problem Analysis to Program Design 1

Introduction to

Windows

Programming

C# Programming: From Problem Analysis to Program Design

4th Edition

9

2

Chapter Objectives

3

Contrasting Windows and Console

Applications

Main()


Graphical User Interfaces

5

Windows Applications

• public class Form1 : Form

6

Windows Applications (continued)

• Text

Main()

– Main() Program.cs

Run()

using System.Windows.Forms; // Line 1

namespace Windows0

{

public class Form1 : Form // Line 2

{

public Form1( ) // Line 3

{

Text = "Simple Windows Application"; // Line 4

}

static void Main( )

{

InitializeComponent(); this.Text = "Simple Windows Application";

}

}

}

1

System.Windows.Forms

Form

Form1 winForm = new Form1( ); Application.Run(winForm);

2

3

4,5

using System.Windows.Forms; namespace Lesson09Prep { public partial class Form1 : Form { public Form1() { InitializeComponent(); this.Text = "Simple Windows Application"; } } }

1

System.Windows.Forms

Form

Form1 winForm = new Form1( ); Application.Run(winForm);

2

3

4,5

Windows Application - Example

9

Windows Application (continued)

Generated

output

10

Elements of Good Design

11

Use Visual Studio to Create Windows-Based Applications

Windows Forms App

(.Net Framework )

Name

Figure 9-2 Visual Studio New Windows application

Select

File New

Project

12

Windows-Based Applications

Properties

Window

Toolbox

Design View

13

Windows-Based Apps

Toolbox


Windows Forms

15

Windows Form Properties

Properties Property value



Figure 9-6 Form events


(continued)

17

Inspecting the Code Generated

by Visual Studio

18

Expand Form1.cs

node to reveal the

Form1.Designer.cs

file

Inspecting the Code - Form1.cs

InitializeComponent( )

19

namespace MyFirstWindowsApp { partial class Form1 { /// <summary> /// ... #region Windows Form Designer generated code /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { this.SuspendLayout(); // // Form1 // this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(629, 455); this.Name = "Form1"; this.Text = "Form1"; this.ResumeLayout(false); } #endregion } }

20

Windows Form Events

Form1.cs

21

Windows Form Properties (continued)

Events button selected

22

Windows Form – Closing Event

public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void Form1_FormClosing(object sender, FormClosingEventArgs e) { MessageBox.Show("Bye - Hope you had fun!", "Leaving this app"); } } }

23

Controls (continued)

Dots

indicate

other

classes

are

derived

from the

class

Figure 9-9 Control class hierarchy

24

Properties of the Control Class

Table 9-2 Systems.Windows.Forms.Control class properties

Properties of the Control Class

(continued)

25 Table 9-2 Systems.Windows.Forms.Control class properties

Methods of the Control Class

26

Table 9-3 includes a

short list of some of the

many methods.

Explore MSDN for

more documentation

Pizza App

27

Pizza App – Form1 Desing

28

btnPlaceYourOrder btnCancelAndClear

lblSides

grpCheese

comSides Items (collection) None Breadsticks Cheesesticks Garlic knots Fries

grpCheese radNormal radDouble radNone

grpShape radRounded radSquared

grpToppings chkPepperoni chkMushroom chkOnions chkAnchovies

txtCustomerName txtPhone

Pizza App – Form2

29

btnQuit

txtOderSummary

btnBack

Pizza App – Form1.cs 1 of 3

30

namespace WindowsFormsApp { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void comSides_SelectedIndexChanged(object sender, EventArgs e) { string selectedItem = comSides.Items[comSides.SelectedIndex].ToString(); if (selectedItem == "None") { lblSides.Text = "Summary of sides: "; } else { lblSides.Text += selectedItem + ", "; } } private void btnPlaceOrder_Click(object sender, EventArgs e) { //this string holds all choices made string choices = ""; //(EXCLUSIVE) obtaining the pizza's shape if (radRounded.Checked) choices += "Rounded, "; else if (radSquared.Checked) choices += "Squared, ";


31

//(EXCLUSIVE) looking into cheese selection if (radCheeseNormal.Checked) choices += "Normal cheese, "; else if (radCheeseDouble.Checked) choices += "Double cheese, "; else if (radCheeseNone.Checked) choices += "No cheese, "; //(INCLUSIVE) collecting all toppings checked by the customer if (chkPepperoni.Checked) choices += "Pepperoni, "; if (chkMushroom.Checked) choices += "Mushroom, "; if (chkOnions.Checked) choices += "Onions, "; if (chkAnchovies.Checked) choices += "Anchovies, "; //(MULTIPLE) extracting Beverage elections from the CheckedListBox var itemList = chkListBeverage.CheckedItems; foreach (var item in itemList) { choices += item + ", "; } //obtaining customer's name and phone choices += "\n" + txtCustomerName.Text + " " + txtPhone.Text; MessageBox.Show(choices, "Quick Summary"); //call other form to display summary Form2 f2 = new Form2(choices, this); f2.ShowDialog(); //try f2.Show(); }


32

private void btnCancel_Click(object sender, EventArgs e) { //clear all side selections lblSides.Text = "Summary of sides: "; //clear all beverage selections for (int i = 0; i < chkListBeverage.Items.Count; i++) { chkListBeverage.SetItemCheckState(i, CheckState.Unchecked); } //individually, clear each topping option chkPepperoni.CheckState = CheckState.Unchecked; chkOnions.CheckState = CheckState.Unchecked; chkMushroom.CheckState = CheckState.Unchecked; chkAnchovies.CheckState = CheckState.Unchecked; } } }


33

namespace WindowsFormsApp { public partial class Form2 : Form { //this variable will be used to remember who called us Form1 form1Reference; public Form2() { InitializeComponent(); } //we added this constructor to accept the order's text and //a reference to the form that called us public Form2(string orderSummaryValue, Form1 callerRefValue) { InitializeComponent(); txtOrderSummary.Text = orderSummaryValue; form1Reference = callerRefValue; } private void btnBack_Click(object sender, EventArgs e) { //go back to our caller, close current form form1Reference.Show(); this.Close(); } private void btnQuit_Click(object sender, EventArgs e) { this.Close(); //closes current form Application.Exit(); //terminates application } } }


Creating a TaxApp

Properties set for the Form

container

Table 9-4 TaxApp Form1 properties


Creating a TaxApp Form

Figure 9-12 Formatting Label objects

Add Label

objects to

Form

object…

Use

options on

FORMAT

menu


Adding Labels to TaxApp Form

Table 9-5 TaxApp label5 object properties

Add Label objects, then set

their properties using the

Properties window

(View Properties window)


TextBox Objects

• Used to enter data or display text during run time

– Used for both input and output

• Instantiate object

TextBox textBoxName = new TextBox( );

• Add control to Form this.Controls.Add(TextBoxName);

• Interesting properties

– MultiLine, ScollBars, MaxLength, PasswordChar, CharacterCasing


TextBox Objects (continued)

Table 9-6 TextBox properties

TextBox Objects (continued)


Table 9-6 TextBox properties (continued)


Adding TextBox Objects to

TaxApp Form Add TextBox objects,

then set their property

values

Table 9-7 TaxApp TextBox objects property changes


Button

• Enables user to click button to perform task

– If button has event-handler method and is registered as

an event to which your program is planning to respond,

event-handler method is called automatically when

button clicked

• Button object’s properties, methods, and events

– Inherits from Control (Table 9-2 & 9-3, slides 31-33)

• Text, Enabled, Focused, TabIndex


Adding Button Objects to

TaxApp Form

Add

Button

objects,

then set

their

property

values

Table 9-7 TaxApp button1 properties


Adding Button

Objects to

TaxApp Form

(continued)

Figure 9-14 Events



TaxApp Form (continued)

•When you double-click on event, an event-

handler method is created: private void btnCompute_Click(object

sender, System.EventArgs e)

{

}

•AND registers click event: this.btnCompute.Click +=

new System.EventHandler

(this.btnCompute_Click);



TaxApp Form (continued) private void btnCompute_Click(object sender, System.EventArgs e)

{

string inValue;

double purchaseAmt, percent, ans;

inValue = txtPurchase.Text;

while (double.TryParse(txtPurchase.Text,out purchaseAmt)==false)

{

MessageBox.Show("Value entered must be numeric");

txtPurchase.Text = "0.0";

txtPurchase.Focus();

} Review TaxApp Example



TaxApp Form (continued) btnCompute_Click( ) ( … continued)

inValue = label5.Text; //inValue previously declared as string

inValue = inValue.Remove(inValue.Length-1, 1);

percent = double.Parse(inValue) / 100;

ans = (purchaseAmt * percent) + purchaseAmt;

txtTotalDue.Text = String.Format("{0:C}", ans).ToString();

}

Parse( ) used

here as opposed

to TryParse( )

…since value is

being retrieve

from TextBox


TaxApp Form

Figure 9-15 Tax calculator output

AcceptButton

property on the

form

was set to

btnCompute


TempAgency

Application

Example

Figure 9-16 Problem specification for TempAgency


TempAgency Application

Example (continued)

Table 9-9 Instance field members for the Employee class

TempAgency Application

Example (continued)


Table 9-10 Constant field members for the Employee class


Figure 9-17 Prototype for TempAgency example

TempAgency Application Example

(continued)


TempAgency

Application

Example

(continued)

Figure 9-18 Class diagrams for TempAgency

example


Algorithm for TempAgency

Figure 9-19 Pseudocode for the Employee class for the

TempAgency example


Test Data for TempAgency

Table 9-11 Desk check test plan of TempAgency example


Properties for TempAgency

Table 9-12 Properties set for the TempAgency example


TempAgency Properties (continued)





Review TempAgency Example


TempAgency Example

Figure 9-20 First user interface for the payroll application


TempAgency Example (continued)

Figure 9-21 Output produced when the Calculate button is clicked

Coding Standards • Guidelines for Naming Controls

– Consistency

– Use appropriate prefix for controls


Table 9-13 Example

prefix identifiers for

controls

Resources

C#: Windows Controls –

http://csharpcomputing.com/Tutorials/Lesson9.htm

Visual C# Tutorials - Windows Forms –

http://visualcsharptutorials.com/windows-forms

Beginners Guide To User Interface Design in C# –

http://www.thetechlabs.com/interfaces/user-interface-design/

Free C# Tutorials –

http://www.homeandlearn.co.uk/csharp/csharp.html


http://csharpcomputing.com/Tutorials/Lesson9.htm









http://www.homeandlearn.co.uk/csharp/csharp.html


Chapter Summary

• Windows versus console applications

• Graphical user interfaces

• Elements of good design

• Visual Studio with Windows-based applications

– Drag-and-drop construction


Chapter Summary (continued)

• Properties

– Getters

– Setters

• Controls as objects

– Buttons

– Labels

– TextBox

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